[Tutor] beginning to code
Bill
BILL_NOSPAM at whoknows.net
Fri Sep 22 03:27:01 EDT 2017
Bill wrote:
> Stefan Ram wrote:
>> Bill <BILL_NOSPAM at whoknows.net> writes:
>>> Stefan Ram wrote:
>>>> bartc <bc at freeuk.com> writes:
>>>>> On 20/09/2017 02:31, Bill wrote:
>>>>>> it's implementation, I would say that C++ has it all over Python
>>>>>> from
>>>>>> the point of view of "intuitiveness". It's much easier to tell
>>>>>> what's
>>>>>> going on, at a glance, in a C++ program.
>>>>> You're being serious, aren't you?
>>>> For one example, this is a part of a C++ program:
>>>> template< typename C >C T( void ( C::* )() );
>>>> . It defines a template T, that can be used in a
>>>> class as follows:
>>>> struct example { void f(); typedef decltype( T( &f )) S; };
>>>> . The type »S« now has a certain property, that can
>>>> be useful sometimes. What is this property (asking Bill)? As
>>> has already been pointed out, one can write "obfuscating code" in any
>>> language, with little effort. I strive to write code which is easily
>>> understandable--and I document it. I don't wish to debate whether I
>>> could make more of a mess in Python, or not.
>> From the point of view of a C++ programmer, the above
>> is not obfuscated, but it is readable and simple C++.
>> It is of course not readable for readers who do not know
>> C++. Just as Python's »string[::-1]« appears "obfuscated"
>> to readers who don't know Python.
>>
>> It was the answer to the question "How can I express the
>> class I'm in in, when I can't write that classes name
>> literally?
>
> I would try to use virtual cast in place of the *&%, I mean code, you
> wrote.
Sorry, I mean dynamic_cast().
> "Clever code" is a losing game--just look at your explanation below.
> Simple==Good.
>
>
>> So, »S« is »example«.
>>
>> It works like this: The type of »&f« is »void ( example::*
>> )()«. So, the function-declaration template »T« infers »C«
>> to be »example«, and the type of »T( &f )« is »example«,
>> which then is transferred to the name »S« using typedef.
>>
>> This is obvious for C++ programmers, but it takes a lot
>> of time to become a C++ programmer, maybe more than it
>> takes to become a Python programmer.
>>
>
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